The present invention is directed to tanks for storing fluids of various sorts. It is particularly applicable to tanks employed in tank trucks, but it is useful for other types of tanks also.
Fluid tanks of the type used on tank trucks typically include an elongated, somewhat tubular shell with internal baffles spaced longitudinally along the axis of the shell to support it. Conventional baffles (often called "heads" when they are fluid tight, particularly if they are disposed at the ends of the tank) come in many different shapes. One shape that is structurally beneficial is the dish-shaped baffle, which takes the form of a sphere segment. While such baffles have desirable structural characteristics, they tend to be expensive to fabricate.
It is less expensive to fabricate baffles having straight vertical cross sections and curved horizontal ones to contribute to vertical stiffness. One baffle of this type has a horizontal cross section shaped something like a flattened m; that is, it has two adjoining concave sections. Another has a sort of curved sawtooth shape in its horizontal cross section. While such baffles are less expensive to fabricate than are dish-shaped baffles, they lend themselves to fatigue and failure at the joints between the tank shell and the baffles.
It is accordingly an object of the present invention to achieve relatively low fabrication costs in a tank that has a low susceptibility to fatigue and failure at the joints between the baffle and the tank shell.